A frame from an 1100-frame time-lapse of the aurora borealis in a modest display from Churchill, Manitoba, January 27, 2017. This was toward the start of the display with the curtains well defined as a classic arc across the north along the auroral oval. Note the dark band separating arcs at top.

This was with the Rokinon 12mm lens at f/2.8 for 10 seconds at ISO 3200 with the Nikon D750.